java 数字格式化 NumberFormat类的使用

最新推荐文章于 2023-06-16 23:17:44 发布

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本文介绍如何使用Java进行数字格式化，包括默认格式化和自定义格式化两种方式。默认格式化能够实现数值的分节显示及小数位数的保留，自定义格式化则提供了更多细节上的控制选项。

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实例1：默认数据格式化

package com.meixin.classuse; import java.text.NumberFormat; public class DefaultNumberFormat { public static void defaultNumberFormat() { int i = 123456; double x = 882323.23523; double p = 0.528; double c = 52.83; System.out.println("--------------------------------------"); //实例化NumberFormat需要使用NumberFormat的getInstance()方法 NumberFormat nf = NumberFormat.getInstance(); //默认格式化int类型，结果已分节 //结果：Integer 123456 is displayed as 123,456 System.out.println("Integer " + i + " is displayed as " + nf.format(i)); //默认格式化double类型，结果保留三位小数，已分节 //结果：Double 882323.23523 is displayed as 882,323.235 System.out.println("Double " + x + " is displayed as " + nf.format(x)); System.out.println("--------------------------------------"); //实例化为整型数据格式化 NumberFormat nfInt = NumberFormat.getIntegerInstance(); //默认，结果：Integer 123456 is displayed as 123,456 System.out.println("Integer " + i + " is displayed as " + nfInt.format(i)); System.out.println("--------------------------------------"); //实例化为数据格式化 NumberFormat nfNumber = NumberFormat.getNumberInstance(); //结果：Double 882323.23523 is displayed as 882,323.235 System.out.println("Double " + x + " is displayed as " + nfNumber.format(x)); System.out.println("--------------------------------------"); //百分数格式化 NumberFormat nfPercent = NumberFormat.getPercentInstance(); //结果已四舍五入 //结果：Percent 0.528 is displayed as 53% System.out.println("Percent " + p + " is displayed as " + nfPercent.format(p)); System.out.println("--------------------------------------"); //货币型格式化 NumberFormat nfCurrency = NumberFormat.getCurrencyInstance(); //结果：Currency 52.83 is displayed as ￥52.83 System.out.println("Currency " + c + " is displayed as " + nfCurrency.format(c)); } public static void main(String[] args) { defaultNumberFormat(); System.out.println(); } }

实例2：自定义数据格式化

package com.meixin.classuse; import java.text.DecimalFormat; public class CustomNumberFormat { public static void customNumberFormat() { double x = 100000.0 / 3; // default output is 33333.333333333336 System.out.println("default output is " + x); // 33,333.33 System.out.println(new DecimalFormat("###,###.##").format(x)); // 33333.33 System.out.println(new DecimalFormat("####.##").format(x)); // 33333.33 System.out.println(new DecimalFormat("####.00").format(x)); // 33333.33 System.out.println(new DecimalFormat("####.0#").format(x)); // 0033333.33 System.out.println(new DecimalFormat("0000000.##").format(x)); // $33,333.33 System.out.println(new DecimalFormat("$###,###.##").format(x)); // 3.333E4 System.out.println(new DecimalFormat("0.###E0").format(x)); // 3333333.33% System.out.println(new DecimalFormat("00.##%").format(x)); System.out.println("--------------------------------------"); double y = 23232323.0012; //default output is 2.32323230012E7 System.out.println("default output is " + y); //23,232,323 System.out.println(new DecimalFormat("###,###.##").format(y)); //23232323 System.out.println(new DecimalFormat("####.##").format(y)); //23232323.00 System.out.println(new DecimalFormat("####.00").format(y)); //23232323.0 System.out.println(new DecimalFormat("####.0#").format(y)); //0023232323 System.out.println(new DecimalFormat("0000000000.##").format(y)); //$23,232,323 System.out.println(new DecimalFormat("$###,###.##").format(y)); //2.323E7 System.out.println(new DecimalFormat("0.###E0").format(y)); //2323232300.12% System.out.println(new DecimalFormat("00.##%").format(y)); } public static void main(String[] args) { customNumberFormat(); System.out.println(); } }